So I thought if I have the value of Kw and I need to find the concentration of [OH-] then all I would have to do is square root the Kw. But in this example, it is not the case why? Kw at 50oC is 5.48x10-14. Calculate OH- concentration so i just square rooted 5.48x10-14 and got 2.34 x10-7. Shouldn't this be right?